مجله علوم و فنون باغبانی ایران
سال بیستم شماره 1 (بهار 1398)

The synchronization of salt stress and dominance of calcareous soils in warm and dry climate regions has led to alkaline salinity stress in vineyards. In this study, the effects of salinity and bicarbonate stresses (alone or in combination) on photosynthetic reactions and nutrient variations of Vitis vinifera ‘Shahroudi’ as a susceptible grape cultivar were evaluated. Using stenting method, scions of this cultivar were grafted on 140Ru, Asgari, and Yaghouti rootstocks. Ungrafted plants were also used to study the impact of rootstocks. Salinity stress which was applied at two levels of zero and 50 mM sodium chloride and bicarbonate stress at two levels of 0 and 5 mM potassium bicarbonate. Results of this study showed significant effect of these three factors (salinity, bicarbonate and rootstock) on catalase activity, transpiration rate, and specific leaf area. Salinity stress reduced total iron content by 36% and alkaline-salt stress decreased 25% of pure leaf photosynthesis. In saline and alkaline conditions, the highest amount of absorbed Cl- and Na+ was observed in Asgari (as compared to ungrafted plants). Results of this study confirmed differences between V. vinifera genotypes in response to salt and bicarbonate stress. Based on this study, Asgari rootstock could be recommended as a suitable rootstock for Vitis vinifera ‘Shahroudi’ in calcareous and saline soils.

In order to evaluate the effects of methyl jasmonate on quality of ‘Rabab’ pomegranate, an experiment was conducted as a completely randomized design with 3 replications. Trees were sprayed with different concentrations of methyl jasmonate (0, 0.1, 0.3, and 0.5 mM) at four different stages of fruit development including full bloom, 30, 60, and 90 days after full bloom.Control trees were sprayed with distilled water. Some quality attributes of the fruit including fruit fresh weight, soluble solids content, pH, total acidity, total phenolics, total antioxidant activity, color index, and ascorbic acid content were evaluated. Methyl jasmonate at a concentration-dependent manner enhanced fruit quality attributes including phytochemical compounds. MeJA at 0.5 mmol L−1 significantly (P≤0.05) enhanced fruit fresh weight, pH, total phenolics, antioxidant activity, and ascorbic acid content and reduced total acidity of fruit juice. Fruits sprayed with 0.5 mmol L−1 caused a significant increase of ‘a’ and chroma indexes. The higher values of L, b value and Hue angel were observed in fruits pretreated with 0.1 mmol L-1 MeJA and control fruit. According to the findings of this study, foliar spraying with 0.5 mmol L−1 MeJA may be considered as an effective nonchemical method for enhancing pomegranate fruit quality attributes and phytochemical compounds.

The purpose of this research was to determine the effects of different silicon concentrations on the physiological and morphological characteristics of purple basil under drought stress conditions. For this purpose, a factorial experiment based on a completely randomized design with three replications was done. The studied factors were four levels of drought stress (25, 50, 75, and 100% full irrigation) and 3 levels of silicon foliar application (0, 1, and 1.5 mM). Results showed that height, number of leaves, dry weight of shoots, and a, b, and total chlorophyll content of the purple basil had a significant decrease with increasing of drought stress (P<0.01). Using silicon especially at1 mM, the damages of drought stress on purple basil was decreased compared to control. Generally, the results of this research represent the positive role of silicon in decreasing the effects caused by drought stress in studied plant.

Citrus trees are susceptible to salinity. In the present study, the response of trifoliate sour orange (Poncirus  trifoliata L.) to the salinity stress at the presence of Arbuscular Mycorrhizal Fungi (AMF) was investigated. Forty-day-old seedlings were inoculated with three species of AMF in combinations including Glomus mosseae + Glomus intraradices, Glomus mosseae + Glomus hoi, Glomus intraradices + Glomus hoi, Glomus mosseae + Glomus intraradices + Glomus hoi and no fungi “control”. After 175 days of inoculation, seedlings were exposed to 35 and 70 mM NaCl for 45 days. Mycorrhizal inoculation especially with the combination of G. mosseae + G. hoi increased the leaves relative water content as well as the amounts of chlorophyll and osmolites. There was a significant reduction in the amounts of malondialdehyde and hydrogen peroxide in the leaves in colonized seedlings compared to the control. The concentrations of Na and Cl in the  leaves were higher when salinity increased, while the concentration of N, P, K, Ca and Mg were significantly decreased. On the other hand, inoculation with AMF resulted in a significant increase in the concentrations of N, P, K, Ca, and Mg in colonized seedlings. In general, AMF was able to help the sour orange seedlings against salinity by increasing the leaf nutrient elements and reducing oxidative damage.

Melatonin (N-acetyl-5-methoxytryptamine) is a highly conserved molecule that is not exclusive to the animal kingdom and its presence in plants has been confirmed by numerous studies. Melatonin has delayed flowering in some day-sensitive plants. When spinach enters the reproduction phase, its nutritional value is markedly reduced. This experiment was conducted to evaluate the effects of melatonin on some growth and flowering traits of spinach based on a completely randomized design with 8 treatments and 12 replications. Treatments included seed priming and foliar application of melatonin at concentrations of 0, 25, 50, and 100 mg L-1. The results showed that leaf area, fresh and dry weight of shoots, the number of lateral roots, chlorophyll content, and the amount of endogenous melatonin in seed-primed plants were increased by 14.8, 21.8, 22, 29.86, 64.78, and 97%, respectively. Flowering time of plants was delayed by exogenous application of melatonin. Plants derived from seeds primed with 100 mg L-1 of melatonin showed greater days to flowering with higher number of leaves at this stage. This delay in flowering was confirmed at the microscopic level by examining the meristems at four-leaf stage. Based on the results of this study, it can be concluded that melatonin delayed the transition to the reproductive phase and left the plant in the vegetative phase by enhancing vegetative growth of the spinach plant.

This experiment was conducted to investigate the effects of active and passive-modified atmosphere packaging (MAP) on quality attributes of pomegranate fruits (Ponica granatum cv. Rabab Ney-Riz) stored at 5°C for 4 months. Fruits were individually packaged in a high barrier polyamide/polyethylene film under active-MA free of Co2 (1% O2 + 99 % N2, 3 % O2 + 97 % N2, 5% O2 + 95 % N2), passive-MA and open top in air. Evaluation of results showed that fruits stored under polyamide/polyethylene film had the minimum weight loss compared to those stored in air. Titratable acid content was increased in all packaging methods with increasing storage time. Titratable acid and total Soluble Solid contents were not influenced by gas composition. High O2 atmosphere (open air) well maintained antioxidant activity of fruits. Contents of total anthocyanin, total phenol and ascorbic acid were affected by the storage atmosphere and time. The Highest contents of total anthocyanin were observed in samples of open air and passive-MAP which increased with the progress of storage time. Total phenolic contents in fruits were highest for 1% O2 packages which had the lowest O2 compared to the other treatments. Ascorbic acid content of fruits was decreased with increase in storage time and revealed the most reduction in samples stored under 3 % O2, 5% O2, and open air.

Aim of this study was the application of some organic materials in soil to improve pot marigold plant (Calendula officinalis L.) tolerance to drought stress. Experiment was performed as factorial based on a completely randomized design with three replications. Treatments were consisted of 100% of pot volume soil (control), 1 and 2 g kg-1 nano-potassioum fertilizer, 30% of pot volume cocopeat (v/v) + 70% soil, 30% of pot volume palmpeat + 70% soil and 30% of pot volume madder plant residues + 70% soil in three levels of drought stress (40, 60, and 80% of field capacity). According to the results, with increasing the drought stress, growth parameters were significantly decreased. The highest plant height (14.3 cm), leaf number (70.3), fresh and dry weight of shoot (79.2 and 11.1 g respectively) and roots (34.06 and 9.3 g respectively) were obtained in interaction of madder plant resideue and 60% field capacity drough stress treatment. In severe stress (40% field capacity), plants in medium with palm peat showed the lowest height (7 cm), leaf number (11.6) and crown diameter (10.1 cm). Generally, results showed that madder plant residues with compared to other treatments increased pot marigold resistance to drought stress. Regard to low cost, high moisture keeping and high porosity of madder plant residues, it could be as a suitable substance in arid land to reduce water consumption.

Withania (Withania coagulans Dunal.) is one of the most economically important plants endemic to Sistan and Baluchestan province in Iran.  This plant is used in landscape, pharmaceutical industries and stabilization of sand in desert areas. Salinity is one of the limiting factors of growth and geographical distribution of plants. This study was conducted to evaluate the effects of salinity stress (sodium chloride and potassium chloride) on some morphological and physiological characteristics of withania. The experiment was laid out based on a completely randomized design with 9 treatments and 4 replications under greenhouse conditions. Treatments were: control (without stress) and sodium chloride and potassium chloride in four levels (50, 100, 150, and 200 mM). The results showed that salinity stress significantly affected proline content, Ioninc leakage percentage, Fluorescence chlorophyll, shoot and root dry weight, root to shoot dry weight ratio, leave surface, root length and survival percentage (P≤1%). Mean Comparisons showed that the highest value of proline and Ioninc leakage percentage respectively 4.27 (μmol g-1 FW) and 45.56% were obtained at 200 mM of NaCl and The least value of proline and Ioninc leakage percentage were observed at control. Morphological indices showed more decline under NaCl treatment compared to KCl. so that, leave surface decreased at 200 mM NaCl (58.45 cm2) compared to 200 mM KC (69.70 cm2). Also, with increasing salinity stress, root to shoot dry weight ratio was increased. The maximum amount of root to shoot dry weight ratio (1.01) was obtained at 200 mM of NaCl. Our findings showed that the tolerance of withania to salinity stress was determined equal to 100 mM, while with increasing salinity stress to 200 mM, percentage of survival was decreased (70.38%) compared to the control. Therefore, based on the obtained results, in addition to the use in landscape, withania can be used in saline areas.

Salinity stress is one of the important environmental factors that reduces the growth and yield of plants, especially in arid and semi-arid regions of the world. To investigate the effect of salinity levels (0.6, 3, and 6 dS m-1) on 3 populations of damask rose (from Fars, Kerman, and Isfahan provinces) a factorial experiment was conducted in a completely randomized design with four replications and some growth and Biochemical parameters were evaluated. Results showed that 6 dS m-1 salinity significantly reduced leaf area in Mayand population and root and shoot dry weight in Kashan population. The reduction of chlorophyll content in the treatment of 6 dS/m was more than that of control in the Meymand population (from 0.44 to 0.3 mg FW). Lalehzar population had the highest proline content (15.84 μmol mg-1 FW) and the highest activity of catalase (8.4 U mg-1 FW), peroxidase (11.76 U mg-1 FW), and superoxide dismutase (17.7 U mg-1 protein) at the concentration of 6 dS m-1. The accumulation of the highest amount of sodium and chloride ions occurred in the leaves. Lalehzar and Meymand populations had the highest concentrations of sodium ions (19.6 μmol g-1 DW) and chlorine (11.51 μmol g-1 DW) at 6 dS m-1, respectively. With increase in salinity levels, the amount of potassium ion in leaf in all three populations did not change significantly, while its increased amount in stem and root was significantly. Lalehzar population had the highest potassium ion in stem (10.89 μmol g-1 DW) and root (6.87 μmol g-1 DW)  at the concentration of 6 dS m-1. Totally, from data obtained in this investigation, it may be concluded that Lalehzar and Meymand populations had the highest and lowest tolerance tolerance to salinity respectively.

Spinach is one the most important vegetables with high qualities that is widely cultivated in northern region of Iran. Environmental stresses are excessively grown up and they are serious threat in quality of cultivated spinach. These stressed generally cause dreadful damages in plant cells via increasing reactive oxygen species (ROS). In this study oxidative stress has been applied by using AgNO3 (0, 1, 2 mM) spray, also peri-treatment of ascorbic acid (0, 20 mM) was used followed by AgNO3 treatment. The measured traits included phenotypic performance, leaf area, dry mass, growth index, leaf protein, chlorophyll and oxidative cellular levels (LOX and TBARM assay) during sampling period (12, 24, 48 h) after sprayed treatments. The New Persian cultivar was used in greenhouse condition with 6 treatments in RBCD design format with 4 replications. Treatments have sprayed at maximum of vegetative growth (maximum leaf area). The results showed sprayed of ascorbic acid had no detrimental effect on studied traits. Whereas, sprayed of AgNO3 caused some decline in the amount of most traits as well as some increase in the content of TBARM and LOX. Nitrate reductase gene expression relatively increased by ascorbic acid compared with control (water spray). Whereas, applying AgNO3 significantly decline nitrate reductase gene expression. However, applying pretreatment of ascorbic acid followed by AgNO3 after 2 h retrieved mostly all studied traits.